ELICOCO
Member
Joined: Jun 26, 2008
Posts: 56
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 Posted: 04/08/2008 4:18 am Post subject: SN74F161A SN54F157A SN74F157A pdf and datasheet |
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SN74F161A SN54F157A SN74F157A pdf and datasheet:http://www.chinaicmart.com/series-SN7/SN74F161A.html
ttable, 4-bit binary ounter features an internal carry look-ahead
circuitry for application in high-speed counting esigns. Synchronous operation is provided by
having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so nstructed by the count-enable (ENP, ENT) inputs and internal gating. This mode of operation eliminates the utput counting spikes that are normally associated with asynchronous (ripple-clock) counters; however, ounting spikes may occur on the ripple-carry (RCO) output. A buffered clock (CLK) input triggers the four lip-flops on the rising (positive-going) edge of the clock input waveform. his counter is fully programmable; that is, it may be preset to any number between 0 and 15. As presetting is ynchronous, setting up a low level at the load (LOAD
) input disables the counter and causes the outputs to gree with the setup data after the next clock pulse regardless of the levels of the enable inputs. |
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